This invention relates to so-called pavers or finishers, of the type adapted to receive aggregate, such as a mixture of crushed rock and asphalt, and then to spread such aggregate as a smooth layer over a surface being paved. In the usual instance, aggregate is supplied to the paver through a dump truck positioned in front of the paver, which dumps aggregate from the dump body of the truck into a receiving hopper provided in the paver.
With larger units having a receiving hopper of appreciable size, problems are experienced in moving the aggregate within the hopper whereby such may fall from the hopper downwardly toward the region being paved and in advance of the screed in the paver which is the instrumentality which smooths and spreads the material on the surface being paved. If the hopper is made tiltable to cause material by gravity to flow downwardly in advance of the screed, problems arise in connection with the dump truck which is supplying the paver. Further explaining, clearance problems arise, with the hopper being tilted, tending to move into the dump body of the truck. This has required what may be referred to as "jack-rabbitting", with the truck having to move forwardly and free of the paver to permit tilting of the hopper, and the truck after the hopper is lowered moving back into proper dumping position to permit dumping of more of its load into the dump body. This obviously is time-consuming and tedious. Alternatively, a conveyer such as a drag chain may be provided along the base of the hopper. However, such are difficult to clean and the return run of the drag chain which of necessity travels under the hopper tends to draw material with it and away from the specific region where paving is being performed. Additionally, it is difficult to accurately control material flow where drag chains are present, since the presence of the chain makes it difficult to incorporate any closure structure operable to prevent material flow at the precise time desired.
In general terms, an object of the invention is to provide a novel paver or finishing machine which takes care of the above and related problems in a highly practical and satisfactory manner.
More specifically, an object of the invention is to provide a paver which includes one, preferably two, rotating discs forming a substantial portion of the floor of the paver which may be operated to produce rearward flow of aggregate to a region where such may cascade downwardly in advance of the screed in the paver.
A somewhat related object is to provide such a paver which, in addition to the discs, includes a tiltable mounting with the hopper being tiltable to cause material by gravity to flow rearwardly and out of the hopper. With the organization contemplated, the discs may be employed to cause rearward movement of much of the load of the dump truck, and to the extent necessary to permit the truck to dump its entire load into the hopper without losing its closely coupled relation with the paver. With the entire load dumped and the truck moved away to receive another load, the hopper may be pivoted completely to clear it of the aggregate supplied by the truck, with the hopper being fully cleared when subsequently lowered to receive aggregate dumped from another truck.
Another object and feature of the invention is the provision of a paver which includes, in effect, a pair of hoppers, comprising a main or collecting hopper which receives material from the dump truck, and another, what is referred to herein as a "feed hopper", which receives material moved from the collecting hopper and controls the flow of such directly in advance of the screed in the paver. With disc means forming the floor of the collecting hopper, the feed hopper may be constructed so as completely to confine material moved from the collecting hopper. Through appropriate control of closure means forming the base of the feed hopper, the amount of material deposited for leveling by the screed may be precisely controlled.
A paver as contemplated herein is relatively easily cleaned and presents minimal maintenance problems. Readily incorporated with the paver are so-called screed extensions and other devices, such as augers, promoting enlarging of the side-to-side dimension of the layer of material spread by the screed, and a uniform distribution of material in a region in advance of the screed.
Another feature and object of the invention is the provision of a novel mounting for the screed in a paver, permitting adjustments to be made in the angle spreading surface of the screed assumes with respect to the area being paved.